Device for forming thin-walled material into a sleeve-shaped body

ABSTRACT

Apparatus ( 1 ) for forming thin-walled material from an essentially flat piece of material ( 2 ) into a sleeve-like body ( 20 ), with two forming dies ( 3, 4 ), at least one of which is configured to be able to move into position against the other one and at least one of the forming dies ( 3, 4 ) is pivoted, while the clearance between the two forming dies ( 3, 4 ) when they are open is so large that the flat piece of material ( 2 ) can be placed between the two forming dies.

The invention relates to an apparatus for forming thin-walled materialfrom an essentially flat piece of material into a sleeve-like body, withtwo forming dies, at least one of which is configured to be able to moveinto position against the other one.

When sheet metal is being formed into a round or oval body, the flatsheet metal or similar material is generally rolled first before theprocess of forming it into a finished body in a mould continues.

DE 197 43 436, for example, discloses such an apparatus, which is verysuitable for forming large numbers of objects.

The purpose of the invention is to design an apparatus of the kindoutlined above in such a way that the forming process can be carried outin a single operation.

In the solution to this problem proposed by the invention, at least oneof the forming dies is pivoted, while the clearance between the twoforming dies when they are open is so large that the flat piece ofmaterial can be placed between the two forming dies.

When one or both forming dies are moved towards each other, the sheetmetal that has been placed between them is bent into the mould that isformed and takes on the shape specified by the two forming dies when thelatter have closed completely.

It is possible in this context to design the apparatus to be extremelysimple with largely manual operation, which is very advantageous forshort series in particular. Configuration for a fully automatic processis, however, also possible.

In an advantageous further development of the invention, fingers thatengage between each other are provided at the end of each of the twoforming dies facing the fulcrum of the forming dies.

The plate can rest against these fingers during the bending operation,although the two forming dies are not yet resting against each other.This therefore makes it impossible for the sheet metal to escape intothe free space below the forming dies.

In another advantageous further development of the invention, acentering element is located at the end of each of the two forming diesfacing away from the fulcrum.

The ends of the sheet metal rest against this centering element duringthe forming process, so that the seam of the body that forms is fixed inthe position specified by the centering elements.

This makes it simple to close this seam by means of welding.

In another very advantageous further development of the invention, thecentering element is pivoted.

This means that each of the two centering elements can be swivelled outof the mould and that the two forming dies can be swivelled togetherinto their final position, in which the body receives its final shape.

It is very advantageous in this context if in accordance with anotherfurther development of the invention the centering element is pivoted ona two-arm lever, the lever arm of which that is facing away from thecentering element is engaged by a cam or similar device.

This makes it particularly easy to carry out the swivelling operation ofthe two centering elements.

In another advantageous further development of the invention, aremovable closure element is provided, preferably next to the centeringelement.

Following completion of the forming operation, the two closure elementsare removed from the forming dies, as a result of which an open gap iscreated, through which the welded seam to close the body can beproduced.

It has proved to be particularly favourable in this context if inaccordance with another further development of the invention the closureelement is provided to permit longitudinal movement.

This longitudinal movement can be made particularly easily.

One embodiment of the invention is illustrated in the drawings:

FIG. 1 is a diagrammatic cross section of a forming apparatus with twoforming dies in their open position,

FIG. 2 shows the forming apparatus illustrated in FIG. 1 in its almostcompletely closed position and

FIG. 3 shows a detail of a forming die on a larger scale.

1 in FIG. 1 is an apparatus that is used to form a sheet metal plate 2into a body 20. The apparatus 1 includes two forming dies 3 and 4, thehollow shape of which corresponds to the outside shape of the body 20when it is formed later on. The two forming dies 3, 4 are pivoted arounda common fulcrum 5, while it is perfectly possible to pivot only one ofthe two forming dies and to configure the other one so that it is in afixed position. Each of the two forming dies 3, 4 is equipped at its endfacing the fulcrum 5 with several fingers 6 and 7, which engage betweeneach other when the two forming dies swivel towards each other. Acentering element 8 and 9, which supports the relevant end of the sheetmetal plate 2, is provided at the top end of the two forming dies 3, 4.When the two forming dies 3, 4 swivel together, the relevant end of thesheet metal plate 2 moves against this centering element 8 and 9 and thesheet metal plate 2 is bent into the shape of the die as is indicated inFIG. 1. In this context, the fingers 6 and 7 prevent the central sectionof the sheet metal plate 2 from being able to escape downwards while thebottom ends of the two forming dies are not yet resting against eachother. As soon as the two forming dies have been closed to such anextent that the centering elements rest against each other, the latterare pulled out upwards and the two forming dies-are moved into positionso that they are resting against each other completely. The two ends ofthe sheet metal plate 2 then rest against each other without a gapbetween them. A closure element 10 and 11 is provided directly next toeach of the two centering elements 8, 9 and can also be removed once thecentering elements have been removed and the two forming dies haveclosed completely. When these two closure elements 10, 11 are pulledout, a gap 12 is created in the mould produced by the forming dies,through which the two ends of the body 20 can be welded to each other.

In FIG. 2, the apparatus 1 is shown almost completely closed after thecentering elements 8, 9 and the closure elements 10, 11 have beenremoved.

FIG. 3 shows the top section of a forming die 4 with the centeringelement 9 provided in it and the closure section 11 on a larger scale.

The centering element 9 is attached to a pivoted lever 30, which isactuated by a cam 31 that is pivoted on a rotating disc 32. A piston 33engages this cam 31, which produces the rotary movement of the disc 32and thus the swivelling movement of the lever 30.

Another piston 34 engages the closure element 11 via several levers 35and 36 and moves this closure element 11 from its closed position to itsopen position and vice-versa.

As is indicated, a spring 37 can also engage the lever 30 of thecentering element and move the lever into the engaged position of thecentering element.

1. Apparatus (1) for forming thin-walled material from an essentiallyflat piece of material (2) into a sleeve-like body (20), with twoforming dies (3, 4), at least one of which is configured to be able tomove into position against the other one, wherein at least one of theforming dies (3, 4) is pivoted, while the clearance between the twoforming dies (3, 4) when they are open is so large that the flat pieceof material (2) can be placed between the two forming dies.
 2. Apparatusaccording to claim 1, wherein fingers that engage between each other areprovided at the end of each of the two forming dies (3, 4) facing thefulcrum (5) of the forming dies (3, 4).
 3. Apparatus according to claim1, wherein a centering element (8, 9) is located at the end of each ofthe two forming dies (3, 4) facing away from the fulcrum (5). 4.Apparatus according to claim 3, wherein the centering element (8, 9) ispivoted.
 5. Apparatus according to claim 4, wherein the centeringelement (8, 9) is pivoted on a two-arm lever (30), the lever arm ofwhich that is facing away from the centering element (8, 9) is engagedby a cam (31, 32) or similar device.
 6. Apparatus according to claim 1wherein a removable closure element (10, 11) is provided, preferablynext to the centering element (8, 9).
 7. Apparatus according to claim 6,wherein the closure element (10, 11) is provided to permit longitudinalmovement.